Long-distance telephone communications serving a local telephone exchange typically involves the employment of multichanneled communications links or routes extending in a number of directions. Each communications route typically employs a communications cable or cables made up of wire or conductor pairs and wherein two pairs, or four wires, are employed for each communications channel and wherein one pair would provide an outward communications for one channel, and the other providing inward communications to that channel. Because of attenuation of telephone signals along a cable, amplifiers are typically required at 1- to 6-mile intervals. These are referred to as repeater amplifiers, or just repeaters, and are housed at repeater stations. When a problem occurs on a particular channel, it is common practice to loop back from a repeater station, to a central office, the incoming and outgoing wire pairs of a communications channel, whereby there is formed a communications loop at the central office, which can thus can be tested at the central office. At present, this often involves a maintenance person having to go to a number of repeater stations along a route in order to isolate that portion of a communications channel which is at fault. Thus, obviously, it would be desirable to be able to remotely and selectively, within a matter of minutes, effect the looping back operation at all of the repeater stations along a route. While the applicant is aware that efforts have been made to do this, he is unaware of any successful efforts.
It is thus the object of this invention to provide a truly effective, remotely controllable, looping back system.